1. Field of the Invention
This invention relates to the deposition of a coating material on a substrate article, and more particularly to cathode sputtering of high temperature materials.
2. Description of the Prior Art
Cathode sputtering is a process known within the art for depositing surface material on a substrate article. Deposition of the material on the article combines preferred properties of the coating material with the preferred properties of the substrate material to produce a composite structure with enhanced capabilities.
In the practice of the cathode sputtering process, a coating material on a sacrificial cathode is bombarded by minute particles, causing a transfer of energy to the surface atoms of the coating material. The energized surface atoms eject from the sacrificial cathode into a sputtering chamber where a portion of the ejected atoms is intercepted by the substrate to be coated. The intercepted atoms impinge upon the surface of the substrate and become adhered thereto. Sequenced depositions on the atomic scale over a period of time produce an even, well adhered film on the substrate. The deposition of high melting point materials, including even ceramics, has been achieved. Notwithstanding the apparent benefits of cathode sputtering, apparatus and techniques for satisfactorily applying thick, high temperature coatings of material within reasonable elapsed periods have not heretofore been developed.
Designers and manufacturers of gas turbine engines are expending substantial economic and personnel resources in the search for new apparatus and procedures capable of rendering cathode sputtering suitable for the rapid deposition of high temperature coatings on parts having complex geometries.